In a number of industries there is a need of mixing particles into fluids. This includes industries such as dairy, food, cosmetic, beverage, pharmaceutical, chemical, plastic, building construction, pulp and paper, oil and gas industries. The purpose of the mixing is to achieve e.g. homogenization, particle size reduction and dispersion of particles in the fluid. A number of technologies for obtaining adequate mixing are used, including rotating shear units, conventional stirring techniques, vibration based techniques, techniques were fluid streams collide etc. The mixing is performed in one or more stages and is typically effect in one or more shearing zones where fluid undergoes “shear”, which happens when fluid travels with a different velocity relative to an adjacent area or fluid volume.
One example of a mixer type is shown in patent document U.S. Pat. No. 3,833,718 which describes a so called jet mixer. This mixer is used for providing high shear mixing of fluids such as in the preparation of slurry solutions for well treating. The mixing principle is based on forming a shear zone at the confluence of opposing streams of a mixture of fluid and particles. The mixer is based on separating the fluid into two streams and then directing the streams towards each other and jetting the two opposing streams in a mixing zone to form a shear zone at the confluence of the merging streams. The streams are directed into the mixing zone from a location substantially at right angles to each other, which effectively accomplishes mixing (shearing).
The described mixer seems to provide adequate mixing. However, it is estimated that a mixer of this type may be improved, for example in respect of its capability to effectively mix particles at a wider range of flow rates of the fluid. Also, it is desirable that the described type of mixer should be able to efficiently mix a greater variety of fluid types and particle types.